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A Microwave-augmented Plasma Torch as an igniter/fuel injector in a supersonic-engine Schematic of a conceptual Ajax vehicle and the engine. A powerful plasma torch (from a few kW to a few hundred kW peak power) is being developed. It is aimed to apply this torch as an igniter/fuel injector in the scramjet engine being developed for the future hypersonic vehicle (as shown above) and for the Mach-8 air to surface missiles. This torch has been tested in a Mach 2.5 wind tunnel; as shown in (b) of the torch images, this torch can withstand the blow by a Mach 2.5 cross flow, which simulates the condition in a supersonic combustor. This torch is now improved to be able to couple additional microwave power into the plasma. A photo of this new invention is shown in the next slide. Torch plasmas in (a) a quiescent environment and (b) in a supersonic crossflow

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Torches (a) without and (b) with adding microwave Microwave-augmented plasma torch module Module works as a fuel injector This new microwave-augmented plasma torch enhances plasma enthalpy and size; it is demonstrated by the difference in the plume images: (a) before and (b) after the magnetron is turned on. This torch module working as a fuel injector was tested by using gaseous ethylene fuel injected through the central electrode tube; the ignited flame plume can be seen in (b). This work is being supported by the AFOSR. Recent Publication: 1. S. P. Kuo, Daniel Bivolaru, Campbell D. Carter, Lance Jacobsen, and Skip Williams, “Operational Characteristics of a Periodic Plasma Torch”, IEEE Trans. Plasma Sci., vol. 32, no. 1, pp , S. P. Kuo and Daniel Bivolaru, “A pulsed torch Plasma in a Mach 2.5 supersonic crossflow,” submitted to IEEE Trans. Plasma Sci..

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ELF/VLF Wave Generation and Applications A major facility for conducting experiments related to basic radio science research as well as DoD missions is under development in Gakona, Alaska, as part of the High Frequency Active Auroral Research Program (HAARP). The antenna array as shown above transmits radio waves with the maximum effective radiated power (ERP) exceeding 1 GW. A key objective of the program is to explore physical processes that can be initiated in the ionosphere and magnetosphere via interactions with high power radio waves. Our participation in this program includes: 1. Developing a Ionospheric Virtual Antenna to generate ELF/VLF waves for communication with submarines 2. Applying VLF waves for controlled precipitation of MeV electrons trapped in the magnetosphere; MeV electrons are harmful to the satellites. This research program is being supported by the ONR and HAARP. Recent Publications: 1. Kuo, S. P. and S. H. Lee, Generation of ELF radiation by ionospheric electrojet modulation using powerful HF heating waves, Radio Sci., 39, RS1S32 (1-5), Kuo, S. P., Paul Kossey, J. T. Huynh, and Steven S. Kuo, Amplification of Whistler Waves for the Precipitation of Trapped Relativistic Electrons in the Magnetosphere, IEEE Trans. Plasma Sci., 32(2), , 2004.